Tapped turbine.



"urrm TURBINE. LIYLIOATIOK FILED JAN. 22, 1913'.

Patented June 3, 1913.

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UNITED STATES PATENT o-FFIoE;

' LUDWIG- CUBELIC, OF CHARLOTTENBURG, GERMANY, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK. i

TAPPED TURBINE.

1 Specification of Letters Patent.

Patented June 3, 1913.

Application filed January 22, 1913. Serial No. 743,550.

To all whom it may concern Be it known that I, LI'DWIG CUnnLIo, asubject of the King of Prussia, residing at- Charlottenburg, Germany,have invented certain new-and useful Improvements in Tapped Turbines, ofwhich the following is a specification. I

This invention relates to elastic fluid turbines, and especially tothose in which a certain partionof the steam, after passing the highpressure stage or stages'of the machine, is led off to supply heating orother industrial systems. Such turbines are frequently provided with anautomatic overflow valve, whichregulates the admission of the surplussteam to the low pressure portion of the turbine \Vhen the demand 9f theheating system is greater than the turbine can supply, it is customaryto supply fresh steam at boiler p essure to the extraction pipe throughan automatically opening auxiliary valve. In this arrangement, however,unless special precautions are taken, high pressure steam will continueto enter the extraction pipe even when the turbine regains its capacityfor furnishing the'entire amount called for by the heating system. Thisof course entails a loss of energy, because the steam which goesdirectly to the heating system performs no useful work in the turbine.Moreover, in case of an overload, or even of an increasing load \on theturbine, the high pressure steam may enter through the extraction pipeand flow to the low pres-.

- tlow valve and the auxiliary valve which admits high pressure steam tothe extraction pipe so that the latter will not open until after theformer has closed, and will close before the overflow valve opens.

The accompanying drawing is a diagrammatic section of a tapped turbineembodying my invention. High pressure steam is supplied to the firststages 1 of the turbine through a main 2. The extraction pipe 3 is ledoff from that portion of the turbine between these stages and the lowpressure stages 4 of the turbine. The overflow valve 5 which controlsthe flow of steam from the extraction chamber 6 to the low pressurewheels is regulated automatically by the pressure in said chamber actingagainst the piston 7 and the spring 8. With an increasing demand forheating steam and a consequent drop in ressure 1n the chamber 6, thevalve 5 will c ose, to reduce the'a'mount of steam taken 'by the lowpressure stages, and Wlll thus tend to maintain the normal pressure inthe chamber 6. A branch pipe 9 leads from the main 2 to the extractionpipe 3, and 1 s controlled by an auxiliary valve 10 which is responsiveto the pressure in said pipe 3; the heating steam acting upon a piston11 and spring '12 to keep said valve 10 closed when the heating steampressufe exceeds a certain value. If the pressure drops, said valve willbe opened b the spring to admit high pressure steam o the heatingsystem, l 1

By means of a throttle valve 13 the effective pressures on the piston 11can be so regulated'with reference to the pressures on the piston 7 ofthe overflow valve that with a rlsing pressure in the heating system thevalve 10 will close before the valve '5 opens, while with a fallingheating pressure the overflow valve will close before the auxiliaryvalve 10 opens. This effect is due to the fact that the spring 12 isweaker than the spring 8, so' that it will yield to the pressure beforethe latter does. The throttle valve 13 enables the attendant to regulatethis action to a. nicety by lessening or increasing the effectivepressure on the piston 11.

In this way all dangerv of high pressure steam reaching the low pressurewheels by way of the branch pipe 9 is obviated, and the leakage of highpressure steam into the heat-' ing system at the time when the turbineis able to supply allthat is needed is prevented.

In accordance with the provisions 4 of I the patent statutes I havedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof;but I desire tohave it understood thatthe apparatus shown is onlyillustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is 1. A tapped turbine provided with an overflow valvecontrolling the low of steam to the low pressure portion of the machine,

for regulating the operations of said valves so that the overflow valvewill close before the auxiliary valve opens and the latter will closebefore the former opens.

2. A tapped turbine provided with an overflow valve automaticallycontrolling the flow of steam to the low pressure portion of themachine, an auxiliary valve controlling the supply of high pressuresteam to the extraction pipe, means rendering said auxiliary valveresponsive to the pressure in the extraction pipe and means forregulating the effect of such pressure on said valve.

-whereby it will not" open until after the overflow valve has closed,and will close be fore the overflow valve opens.

3. A tapped turbine provided with an overflow valve automaticallycontrolling the flow 0 team to the low pressure portion of the machine,an auxiliary valve controlling a branch main leading from the highpressure main to the extraction pipe, :1 springactuate d piston foroperating said valve, a pipe conveying pressure from the extractionpipeto said piston, and a throttle valve controlling the admission of suchpressure.

In witness whereof, I have hereunto set my hand this 6th day of January,1913.

LUDW IG CUBELIG.

Witnesses FRIEDRICH GANZERT, OTTO SCHMIDT.

